Floor block



Feb. 25, 1936 c. c. FULBRl-GHT FLOOR BLOCK Filed. Feb. 19, 1935 Patented Feb. 25, 1936 UNITED STATES PATENT GFFICE Fri-oon BLOCK carence o. Fulbright, rin'e Bluff, Ark. Application February 19, 1935, serial Nt. 1,259 7' Claims. (ci. zii- 8) `The invention relates to' floor blocks'of the sort which are falciric'atedv of slats assembled at the rnillread-y for assembly with other blocks at the job to forni a floor.

For many years it has been known to assemble iloor blocks at the mill, British patent to Seiler No. 684 of 1851i showing such practice', utilizing iron or wooden splines inserted into grooves inthe baelof the block.

In all such blocks of which I am aware, the splines have only the function of holding the blocks in assembly, and to resist warping purely bythe hold of the'spline. The resistance to warping of suchy blocks has depended entirely upon the hold the splines have upon the material of the slats of which the blocks are composed, either by virtue of glue' or dovetailing, in the case of wooden splines or dowels, or' of some biting into the" wood of the slats, inthe casel of metal splines` Once such blocks are warped or separated by exparision andl subsequent contraction, with consequent slippage of the hold, there hasy been little if any action on thepart of the spline' to again return the block to a plane surface or to draw the slats backtogether.

It is an object of the present invention to provide aA contractile spring acting to hold slats into assembly to form a flooring block.

It is a further object of the invention to provide a contractile spring acting also as a spline to hold the slats into assembly in a block and to maintain them in a` common plane.

It is la further object of the invention to provide a block comprising slats held together by a contractile spring acting to hold the slats in a common plane and to draw the slats together when they become separated.

It is a further object of the invention to provide a block formed of slats held together by a spline placed in their bottom, the spline having resiliency to allow flexure of the block and serving as a contractile spring to return the blocks to their original plane when moved therefrom.

Further objects of the invention will appear from the following description when read in connection with the accompanying drawing showing illustrative embodiments of the invention, and wherein:-

Figure 1 is a bottom plan View of an assembled block;

Fig. 2 is a section on line 2--2 of Fig. 1;

Fig. 3 is a like section showing a different form varying in details from that of Figs. 1 and 2; and

Figs. 4 and 5 are plan views respectively of forms of spring which may be used in the invention.

As shown, the nished block is formed of slats I' des'irably, but not necessarily, formed of hollow backed flooring, the assembled block having tongues II- on two sides thereof and grooves I2 on the remaining two sides with the juncture of the tongues cut away at an angle as at I3 for convenience in assembly in a floor, all of which is common practice.

To hold the blocks in assembly, I provide a contractile spring. As shown the spring comprises either a`A coil .spring as Ill, as shown in Figure 4, or a split ring as I4 shown in Figure 5. The coil spring I4 is the form of spring which I at present prefer and when it is in position in the block, as shown in Figure 1, it will be straightened against its contractility into a circular form with its ends somewhat spaced apart. When the form of Figure 5, as shown at I4 is used, the contractility depends upon the greater spacing between the ends', as shown in Figure 1, than the spacing of said ends' before insertion in the block. The ccntractile spring either I4 or I4 is shown as placed into a groove I5 which is formed in the slats Ill after they are placed together ready for reception of the spring, the groove thus formed in the assembled blocks preferably taking the form of a circle, as shown.

When the joints between the blocks are formed as shown in Figure 2 with a relief I6 at the back of the block, the groove I5 is preferably formed with what might be called a draft as indicated at I1; that is to say, the groove considered as a whole at the open side thereof is not a frustoconical surface lfor substantially one-half the depth of the groove. This form of groove has two objects, rst, it assists in the insertion of the spring, and second, it places the contractile action of the spring above the central transverse plane of the block, so that the contractility of the spring acts as near as possible to the upper surface of the block where the upper edges of the slats are in Contact to form a close joint.

However, when the blocks are formed with square edges, as shown in Figure 3, that is, without the relief at the bottom of the joints, it is desirable to make the groove Il perpendicular to the plane of the blocks in both of its sides.

The assembled block of the invention is found to have considerable flexibility and if bent out of its normal plane, it will when released return to said plane. Moreover, if the slats of the block become separated, as by swelling and subsequent drying, the blocks, particularly when subject to the action of traffic, will tend to return to a tight position by action of the contractile spring.

The return of the slats to plane after flexure is due not only to the rigidity of the spring which must be bent out of its normal plane with edgewise flexure thereof when the block is warped, but such action also creates a strain against the contractility of the spring, since any two points in the groove at a joint between the slats are separated by such warping, thereby pulling the spring against its contractility and thus enlarging the circle of the groove. Such pulling causes the spring to bind against the inner surface of the groove.

As shown the spring is inserted into the groove so that the edge comes substantially flush with the bottom surfaces of the hollow backs in the block and therefore the spring considered as a spline will not interfere with the continuous nature of said hollow back grooves. When the blocks are laid in mastic in accordance with the common practice, the flow of mastic in the grooves will therefore not be interfered with.

Minor changes may be made in the physical embodiments of the invention within the scope of the appended claims without departing from the spirit thereof.

I claim:

1. A block of the class described comprising, in combination: a plurality greater than two of assembled slats; said assembly having a groove in one of its surfaces extending in the outer slats at an angle other than ninety degrees to the points between said slats; and a resilient spline lying in said groove under tension tending to draw said slats together.

2. A block of the class described comprising, in combination: a plurality greater than two of assembled slats; said assembly having a groove in its lower surface comprising an arc of a continuous curve cutting across each joint between said slats; a resilient spline lying in said groove under tension tending to draw said slats toward each other.

3. A block of the class described comprising, in combination: a plurality greater than two of assembled slats having an annular groove in the bottom surface of the assembly, cutting across each of the joints thereof; a resilient divided spline lying in tension in and substantially coextensive with said groove acting to urge said slats toward each other.

4. A block of the Class described comprising, in combination: a plurality greater than two of assembled slats, the joints between said slats formed to provide relief at the lower surface of the assembly; an annular groove in the lower surface of said assembly, cutting across each of said joints and penetrating beyond the plane midway between the lower and upper surfaces of the assembly; the inner surface of said groove lying in a frusta-conical surface for at least a portion of its depth; a resilient spline lying in tension in said groove and exerting compressive stress above said plane to tend to keep the joints of said assembly closed at the upper surface thereof.

5. A block of the class described comprising, in combination: a plurality greater than twoof assembled slats having an annular groove in the lower surface of the assembly cutting twice across each of the joints thereof; and a divided, resilient ring spline expanded against its resilience lying in and substantially ooextensive with said groove.

6. A block of the class described comprising, in combination: a plurality greater than two of assembled slats having an annular groove in the lower face of the assembly cutting twice across each of the joints thereof; and a resilient spline initially of spiral form expanded to annular form and embedded in said groove, acting to press said slats toward each other and to resist warping of the assembled block.

7. A floor block comprising, in combination: a plurality greater than two of slats assembled in edgewise engagement and having an annular groove formed in a surface of the assembly cutting twice across each joint between slats thereof; and a resilient divided spline lying in tension in and substantially coextensive with said groove; an exposed edge of said spline standing substantially flush with portions at least of the surface of the assembly in which said groove is formed.

CLARENCE C. FULBRIGHT. 

